1. Field of the Invention
There are many articles of commerce containing elements of such materials as glass, metal or synthetic resins, e.g., crystalline acetal polymers, whose surfaces are bonded to other surfaces of elements composed of like or unlike materials. Some of these articles are, for example, laminated structures such as safety glass, multilayered plastic products, and various complex structures containing different elements bonded to each other. For the purpose of fabricating these articles, the use of any bonding resins capable of providing strong, stable composite structures is very beneficial.
This invention relates to articles comprising elements having surfaces bonded together by means of any of certain elastomeric acetal copolymer bonding resins as hereinafter defined, which have little or no crystallinity at room temperature (about 25.degree. C.). It has been found that the bonding force of elements bonded together with these elastomeric acetal copolymer bonding resins is particularly strong.
Particularly useful under the invention are articles in which the elastomeric acetal copolymers are used as bonding resins between two surfaces of a crystalline acetal polymer or between the surfaces of crystalline acetal polymers and other materials such as glass, metal or wood.
2. Description of Related Art
The following prior art references are disclosed in accordance with the terms of 37 CFR 1.56, 1.97 and 1.98.
U.S. Pat. No. 3,639,192, issued Feb. 1, 1972 to Burg et al., discloses for use as adhesives copolymers of formaldehyde or trioxane with 1 to 60% by weight, preferably 1 to 30% by weight, of a cyclic ether, cyclic and/or linear acetal, e.g., 1,3-dioxolane, and/or an alkyl glycidyl formal, polyglycol diglycidyl ether or bis (alkane triol) triformal. Example 5 discloses a terpolymer of 97.95 wt. % of trioxane, 2 wt. % of ethylene oxide, and 0.05 wt. % of 1,4-butanediol diglycidyl ether.
U.S. Pat. No. 3,337,507, issued Aug. 22, 1967 to Gutweiler et al., teaches the formation of high molecular weight copolymers obtained by polymerizing a mixture of trioxane and any of certain polyformals. Example 4 of the patent shows the use of a polyformal which is a clear highly viscous oil at 70.degree. C. obtained by polymerizing a mixture of 1/3 mole of trioxane and 1 mole of dioxolane in the presence of p-nitrophenyl-diazonium fluoroborate as catalyst.
Japanese Kokai Sho 42-22065 of Yamaguchi et al., published October 30, 1967, discloses copolymers of trioxane and an aperiodic ring compound, e.g., 1,3-dioxolane, prepared in liquid sulfur dioxide, and in Example 1 shows a copolymer of trioxane and 64 mol % of 1,3-dioxolane.
Pending application Ser. No. 096,187, filed Sept. 14, 1987 by Collins et al. now U.S. Pat. No. 4,788,258, issued Nov. 29, 1, discloses and claims certain copolymers of trioxane with from 65 to 75 mol percent of dioxolane, having an IV of about 1.0 to 2.3, which are useful as blending and adhesive agents for conventional crystalline acetal polymers.
Pending application Ser. No. 096,189, filed Sept. 14, 1987 by Collins et al., now U.S. Pat. No. 4,816,107, discloses and claims bonded articles of conventional crystalline acetal polymers wherein the bonding agents are certain copolymers of trioxane with from 65 to 75 mol percent of dioxolane, having an IV of about 1.0 to 2.3.
Pending application Ser. No. 243,381 filed Sept. 12, 1988, by G Collins et al., now U.S. Pat. No. 4,898,925 issued Feb. 6, 1990, discloses the elastomeric acetal copolymers contemplated as bonding resins under this invention. The entire disclosure of this application is incorporated herein by reference.